Scheduling method for processing equipment

Abstract

Methods and apparatus for improving substrate throughput prior to processing a plurality of substrates in a cluster tool having a plurality of processing chambers and at least two robots are provided. The method comprises developing a process sequence, storing the process sequence on a storage device, and transferring the process sequence from the storage device to a controller in communication with the cluster tool. The process sequence comprises depositing one or more uniform resist layers on the surface of the plurality of substrates, transferring the plurality of substrates out of the cluster tool to a separate stepper or scanner tool to pattern the surface of the plurality of substrates by exposing the resist layer to a resist modifying electromagnetic radiation, and then developing the patterned resist layer.

1 . A method of improving substrate throughput prior to processing a plurality of substrates in a cluster tool having a plurality of processing chambers and at least two robots, comprising: 
 planning a schedule and the corresponding actions performed by each component of the cluster tool;    storing the schedule on a storage device; and    transferring the schedule from the storage device to a controller in communication with the cluster tool.    
   
   
       2 . The method of  claim 1 , wherein the planning a schedule comprises: 
 defining constraint conditions;    developing rules incorporating the constraint conditions;    developing a set of proposed schedules;    defining specific characteristics of the proposed schedules;    ensuring that the proposed schedules are executable by the cluster tool; and    selecting at least one of the proposed schedules.    
   
   
       3 . The method of  claim 2 , wherein the developing rules incorporating the constraint conditions comprises: 
 defining process flow steps for scheduling and required throughput;    estimating a number of processing chambers required within the cluster tool;    partitioning the process flow steps to the at least two robots;    defining candidate transition points within the cluster tool;    mapping out chamber zones and moves for the at least two robots;    building a master move table;    recalculating the exchange time to verify chamber capacity;    distributing slack time; and    defining bottle neck resources.    
   
   
       4 . The method of  claim 1 , further comprising controlling the transfer of a plurality of substrates through the plurality of processing chambers according to the planned schedule.  
   
   
       5 . The method of  claim 1 , further comprising depositing one or more uniform resist layers on the surface of the first substrate.  
   
   
       6 . The method of  claim 5 , further comprising transferring the first substrate out of the cluster tool to a separate stepper or scanner tool to pattern the substrate surface by exposing the resist layer to a resist modifying electromagnetic radiation and then developing the patterned resist layer.  
   
   
       7 . The method of  claim 4 , wherein the controlling the transfer of a plurality of substrates through the plurality of processing chambers according to the planned schedule comprises: 
 transferring a first substrate within the cluster tool using a first robot assembly, wherein transferring the first substrate includes removing the first substrate from a first position and placing the first substrate in a second position;    transferring a second substrate within the cluster tool using a second robot assembly, wherein transferring the second substrate includes removing the second substrate from a third position and placing the second substrate in a fourth position;    synchronizing the removing the first substrate with the removing the second substrate or placing the second substrate during a first period of time; and    synchronizing the placing the first substrate with the removing the second substrate or the placing the second substrate during a second period of time, wherein the first period of time and the second period of time are distinct and non-overlapping.    
   
   
       8 . The method of  claim 2 , wherein the selecting at least one of the proposed schedules further comprises displaying the proposed schedules for comparison with a standard schedule.  
   
   
       9 . The method of  claim 4 , wherein the controlling the transfer of a plurality of substrates through the plurality of processing chambers according to the planned schedule comprises: 
 introducing a first lot of wafers containing one through n-th wafers into a cluster tool containing one or more processing chambers;    processing the first lot of wafers for a first time period;    introducing a second lot of wafers containing one through n-th wafers into the cluster tool prior to completion of the first time period, wherein the second lot is introduced so as to minimize a time gap between the n-th wafer of the first lot of wafers and the first wafer of the second lot of wafers while maintaining a first constant wafer history for each wafer within the first lot and maintaining a second constant wafer history for each wafer in the second lot; and    processing the second lot of wafers for a second time period during at least a portion of the first time period.    
   
   
       10 . The method of  claim 1 , further comprising: 
 measuring metrology data for processing a lot of substrates on the cluster tool prior to planning a schedule.    
   
   
       11 . The method of  claim 1 , wherein planning a schedule further comprises resolving robot conflict to provide the highest robot limited throughput.  
   
   
       12 . A method for improving substrate throughput prior to processing a plurality of substrates in a cluster tool having a plurality of processing chambers and at least two robots, comprising: 
 developing a process sequence, wherein the process sequence comprises: 
 depositing one or more uniform resist layers on the surface of the plurality of substrates;  
 transferring the plurality of substrates out of the cluster tool to a separate stepper or scanner tool to pattern the surface of the plurality of substrates by exposing the resist layer to a resist modifying electromagnetic radiation, and then  
 developing the patterned resist layer  
   storing the process sequence on a storage device; and    transferring the process sequence from the storage device to a controller in communication with the cluster tool.    
   
   
       13 . The method of  claim 12 , wherein the developing a process sequence comprises: 
 defining constraint conditions;    developing rules incorporating the constraint conditions;    developing a set of proposed schedules;    defining specific characteristics of the proposed schedules;    ensuring that the proposed schedules are executable by the cluster tool; and    selecting at least one of the proposed schedules.    
   
   
       14 . The method of  claim 13 , wherein the developing rules incorporating the constraint conditions comprises: 
 defining process flow steps for scheduling and required throughput;    estimating the number of processing chambers required within the cluster tool;    partitioning the process flow steps to the at least two robots;    defining candidate transition points within the cluster tool;    mapping out chamber zones and moves for the at least two robots;    building a master move table;    recalculating the exchange time to verify chamber capacity;    distributing slack time; and    defining bottle neck resources.    
   
   
       15 . The method of  claim 13 , wherein defining constraint conditions further comprises minimizing the effects of planned delays.  
   
   
       16 . A system for processing a substrate, comprising: 
 a cluster tool having a plurality of processing chambers and at least two robots;    a controller in communication with the cluster tool;    a memory coupled to the controller;    an offline server;    a storage device coupled to the offline server; and    a memory coupled to the offline server, the memory comprising a computer-readable medium having a computer-readable program embodied therein for improving the throughput of substrates in the cluster tool, the computer-readable program comprising: 
 computer instructions for developing a recipe for improving substrate throughput in the cluster tool by controlling the movements of the at least two robots, the computer instructions comprising: 
 i. planning a schedule and the corresponding actions performed by each component of the cluster tool;  
 ii. storing the schedule on the storage device; and  
 iii. transferring the schedule from the storage device to the controller.  
 
   
   
   
       17 . The system of  claim 16 , wherein the computer instructions further comprise: 
 defining constraint conditions;    developing rules incorporating the constraint conditions;    developing a set of proposed schedules;    defining specific characteristics of the proposed schedules;    ensuring that the proposed schedules are executable by the cluster tool; and    selecting at least one of the proposed schedules.    
   
   
       18 . The system of  claim 16 , wherein the schedule is transferred from the storage device to the controller in communication with the cluster tool.  
   
   
       19 . The method of  claim 17 , wherein the developing rules incorporating the constraint conditions comprises: 
 defining process flow steps for scheduling and required throughput;    estimating the number of processing chambers required within the cluster tool;    partitioning the process flow steps to the at least two robots;    defining candidate transition points within the cluster tool;    mapping out chamber zones and moves for the at least two robots;    building a master move table;    recalculating the exchange time to verify chamber capacity;    distributing slack time; and    defining bottle neck resources.    
   
   
       20 . The system of  claim 16 , wherein the cluster tool comprises: 
 a first processing rack containing a first vertical stack of substrate processing chambers;    a first robot adapted to transfer a substrate to a substrate processing chamber in the first processing rack;    a second processing rack containing a first vertical stack of substrate processing chambers; and    a second robot adapted to transfer a substrate between a substrate processing chamber in the first processing rack and a substrate processing chamber in the second processing rack.    
   
   
       21 . The system of  claim 20 , wherein the substrate processing chambers are each selected from one of the following: a coater chamber, a developer chamber, a HMDS chamber, a chill chamber, or a bake chamber.  
   
   
       22 . The system of  claim 16 , wherein the cluster tool further comprises: 
 a third robot adapted to transfer a substrate among the substrate processing chambers within a first time period.